POWER CONTROLLER FOR HYBRID VEHICLE

• US 20090063007A1
• Filed: 07/31/2008
• Published: 03/05/2009
• Est. Priority Date: 08/31/2007
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: MASUDA, Eiji
• Granted Patent: US 8,280,570 B2
• Time in Patent Office: Days
• US Class Current: 701/102
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/10 including control of change-speed gearings
• CPC Class Codes: B60W 10/24 including control of energy storage means
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart

Abstract

An operation point of the engine where the fuel economy is optimal is obtained based on an iso-fuel-economy curve which is defined by engine speed and engine torque. Each of the operation points is connected to each other to form an efficiency characteristic line on which the demand operation point is computed. When the operation point of the engine is moved in a direction in which the fuel economy is improved, the moving speed of the operation point is increased so that the operation point rapidly moves to the point of high fuel economy as soon as possible. Contrary, when the operation point moves in a direction where the fuel economy is deteriorated, the moving speed of the operation point of the engine is decreased so that the operation point can be moved toward the point of low fuel economy as slow as possible.

Claims

1. A power controller for a hybrid vehicle having an engine and an electric motor as power source, the power controller comprising;

a demand power computing means for computing a demand power of the engine;

a demand operation point computing means for computing a demand operation point of the engine based on the demand power of the engine and an efficiency characteristic of the engine; and

a control means for controlling an operation point of the engine according to the demand operation point, wherein

when the control means moves the operation point of the engine according to the demand operation point, a moving speed of the operation point is changed between a case where the operation point moves to improve a fuel economy and a case where the operation point moves to deteriorate the fuel economy.

2. A power controller for a hybrid vehicle according to claim 1, further comprising an abrupt acceleration demand detecting means for detecting an abrupt acceleration demand of a driver, wherein

when the abrupt acceleration demand is detected, the control means gives a priority to the abrupt acceleration demand over the fuel economy and changes the moving speed of the operation point according to the abrupt acceleration demand.